Study links chronic diseases to higher sepsis risk

Having chronic lung, kidney or heart disease more than doubles a personís risk of future sepsis, according to a study, which also found the risk increases by 85% in people who have had a stroke and 71% in those who have diabetes.

Moreover, the risks from each condition are additive, reported researchers with the University of Alabama at Birmingham.

Severe sepsis strikes about 750,000 Americans a year, most of them older and often ill, with about 200,000 dying, according to background information for the study, which appeared Oct. 31 in the online journal PLOS ONE.

Henry Wang, MD, vice chairman for research in the Department of Emergency Medicine at UAB, used data from the REGARDS (Reasons for Geographic and Racial Differences in Stroke), a stroke study of 30,000 black and white middle-aged adults over an eight-year span.

In a previous study, researchers used data to reveal that sepsis is twice as common in the stroke belt, a cluster of 11 southeastern and mid-Atlantic states. The latest study provides possible explanations.

In general, the researchers found that sepsis risk is most closely associated with older age, lower education and income and smoking and drinking alcohol. Men are at greater risk than women, according to the new analysis, and whites have a higher risk than blacks, which "flies in the face of the current understanding," Wang said in a news release. Blacks in the sepsis belt might be less likely to report an infection or lack access to care, Wang suggested, but the team awaits a more complete data analysis for more authoritative answers.

The study provides the first evidence pointing to factors that increase risk of future sepsis, but it does not yet explain why sepsis overlaps with stroke and other chronic diseases. One theory, Wang said, is that the overlap is caused by chronic inflammation in the cells lining the blood vessels. The mechanisms causing arteries to become diseased may over time make the immune system hypersensitive to viral, bacterial and fungal infections.

Regardless, understanding the risk factors may enable the design of new public health interventions, including awareness campaigns. Current anti-sepsis initiatives focus on acute care, with ED staff employing the "sepsis bundle," a series of steps that includes aggressive administration of antibiotics, IV fluids and blood pressure-boosting medications. Despite the bundleís effectiveness, many EDs still "fail to take all of the steps, or to take them quickly enough," Wang said. Hospitals need to avoid these crises altogether by concentrating on long-term prevention, but almost no resources are focused on that goal.

The authors emphasized that the current study does not establish any chronic disease as a cause of sepsis. Should such connections be established, however, preventive care such as glycemic control, smoking cessation and aggressive vaccination could become recognized as protective against both chronic diseases and sepsis.

The effect of obesity on sepsis risk is the subject of a separate REGARDS-based study by the UAB team, which is expected out shortly.